Analog Devices Inc./Maxim Integrated MAX14948EWE+T

Overview

MAX14948EWE+T from Maxim Integrated is a 5kVRMS galvanically isolated, half-duplex RS-485/RS-422 transceiver with integrated LDO, ±30kV HBM ESD protection on A/B pins, 500kbps data rate, and true fail-safe receiver. It breaks ground loops in industrial networks and supports up to 256 nodes on a single bus.

For engineers reviewing the MAX14948EWE+T datasheet, MAX14948EWE+T pinout, MAX14948EWE+T application, or MAX14948EWE+T equivalent, key selection considerations include isolation voltage rating (5000VRMS/60s), cable-side LDO capability (5V/300mA), thermal shutdown threshold (+160°C), and 1/8-unit-load receiver compatibility with dense multi-drop buses.

Technical Context

The MAX14948EWE+T implements capacitive galvanic isolation between UART-side (GNDA/VDDA) and cable-side (GNDB/VDDB/VLDO), enabling robust communication across ground-potential differences up to ±12V common-mode range. Its integrated 5V LDO (VLDO input ≥4.68V) powers the isolated side and features 300mA current limit and 100–180mV dropout.

It uses true fail-safe receiver architecture with fixed differential threshold (–200mV to –50mV) and hysteresis (15mV), ensuring logic-high RXD during open/shorted bus conditions. Driver outputs feature foldback current limiting and thermal shutdown at +160°C (15°C hysteresis), while CMTI is rated at 35kV/μs for noise immunity.

Key Specifications

Pinout & Package

MAX14948EWE+T is housed in a wide-body 16-pin SOIC (W16M+9, 8mm creepage/clearance), RoHS-compliant, with exposed die pad not connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated RS-485 transceiver applications.

Compared with ISO1500DR and ADM2483BRWZ, the MAX14948EWE+T provides higher isolation (5000VRMS/60s), stronger ESD (±30kV), and greater bus node capacity (256), making it optimal for mission-critical industrial infrastructure where reliability and density are prioritized over minimal BOM count.

Availability

MAX14948EWE+T is available at Aetrix Electronics and suitable for industrial automation equipment, programmable logic controllers, and HVAC systems requiring stable component supply, long-term lifecycle support, and certified galvanic isolation.

Supply support for MAX14948EWE+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated, now part of Analog Devices, designs precision analog, mixed-signal, and high-reliability ICs for industrial, automotive, and communications markets.

The MAX14948EWE+T belongs to Maxim's isolated interface product line, engineered specifically for noise-immune, ground-loop-free RS-485/RS-422 communication in harsh industrial environments.

FAQ

What is the maximum data rate supported by the MAX14948EWE+T?

The MAX14948EWE+T supports a maximum data rate of 500kbps, verified across the full operating temperature range (–40°C to +85°C) with RL = 54Ω and CL = 50pF. This rate is maintained with guaranteed propagation delay (tDPLH/tDPHL ≤ 1040ns) and skew (≤144ns), enabling reliable high-speed industrial serial communication without timing violations.

Does the MAX14948EWE+T require external power on the isolated (cable) side?

No-the MAX14948EWE+T includes an integrated LDO that generates 5V (±5%) at up to 300mA from a VLDO input of 4.68V–14V. If external 5V is available on the cable side, VLDO can be tied to GNDB and VDDB used directly as the supply input, eliminating the need for an external regulator.

How does the true fail-safe feature of the MAX14948EWE+T work?

The MAX14948EWE+T's true fail-safe receiver guarantees a logic-high RXD output when A/B inputs are open, shorted, or connected to a terminated bus with all drivers disabled. This is achieved via fixed differential threshold (–200mV to –50mV) and hysteresis (15mV), eliminating reliance on external bias resistors and ensuring deterministic idle-bus behavior.

What safety certifications apply to the MAX14948EWE+T?

The MAX14948EWE+T is certified to UL1577 (File E351759) and CSA Bulletin 5A for 5000VRMS isolation (60s). It also meets IEC 60747-5-5 with VIORM = 1200VPK, VIOWM = 848VRMS, and withstands ±10kV surge per IEC 61000-4-5, supporting compliance in industrial safety-critical designs.

Can the MAX14948EWE+T drive more than 32 devices on an RS-485 bus?

Yes-the MAX14948EWE+T features a 1/8-unit-load receiver, allowing up to 256 transceivers on a single RS-485 bus segment. This is four times the node count of standard 1-unit-load receivers, reducing need for repeaters and simplifying large-scale industrial network topologies.